[dpdk-dev] [PATCH v3 08/12] app/eventdev: add pipeline queue test

[Van Haaren, Harry]

> From: Pavan Nikhilesh [mailto:pbhagavatula at caviumnetworks.com]
> Sent: Wednesday, January 10, 2018 2:52 PM
> To: jerin.jacob at caviumnetworks.com; santosh.shukla at caviumnetworks.com; Van
> Haaren, Harry <harry.van.haaren at intel.com>; Eads, Gage
> <gage.eads at intel.com>; hemant.agrawal at nxp.com; nipun.gupta at nxp.com; Ma,
> Liang J <liang.j.ma at intel.com>
> Cc: dev at dpdk.org; Pavan Nikhilesh <pbhagavatula at caviumnetworks.com>
> Subject: [dpdk-dev] [PATCH v3 08/12] app/eventdev: add pipeline queue test
> 
> This is a pipeline queue test case that aims at testing the following:
> 1. Measure the end-to-end performance of an event dev with a ethernet dev.
> 2. Maintain packet ordering from Rx to Tx.
> 
> The pipeline queue test configures the eventdev with Q queues and P ports,
> where Q is (nb_ethdev * nb_stages) + nb_ethdev and P is nb_workers.

Why (nb_ethdev * nb_stages) number of Queues?

I had expected if the test is for eventdev with Q queues, P ports, that that Q number of stages is all that is required, (possibly with +1 for TX queue, iirc some HW doesn't require the TX Queue).

Am I missing something here? I've left the code snippet I don't understand below.


<snip>

> Note: The --prod_type_ethdev is mandatory for running the application.

Mandatory arguments seem pointless to me, unless there are other valid options to choose from.


> +
> +static int
> +pipeline_queue_eventdev_setup(struct evt_test *test, struct evt_options
> *opt)
> +{
> +	int ret;
> +	int nb_ports;
> +	int nb_queues;
> +	int nb_stages = opt->nb_stages;
> +	uint8_t queue;
> +	struct rte_event_dev_info info;
> +
> +	nb_ports = evt_nr_active_lcores(opt->wlcores);
> +	nb_queues = rte_eth_dev_count() * (nb_stages);


As per comment above, this is what I don't understand? Why more queues than stages?